Optical module and method for reducing color desaturation in an optical module

Abstract

A light module (10) for a lighting device (2) of a vehicle (1), the light module having at least one light emitting device (19) and a light guide (24) which is suitable and determined for guiding rays which emanate from the light emitting device (19) and which are coupled into the light guide to a light exit face (A) of the light guide (24), the light module having at least one rear wall means (20) which is arranged at least partially in the light path of ambient rays (44) which are incident into the light guide (24) from the outside through the light exit face (A) of the light guide (24). According to the invention, the rear wall means (20) has at least one first rear wall region (32, 56, 67) and at least one second rear wall region (34, 57, 66), wherein the at least one first rear wall region (32, 56, 67) and the at least one second rear wall region (34, 57, 66) differ from one another in particular with respect to reflection and / or absorption properties with respect to the ambient rays (44).

Description

Technical Field

[0001] This invention relates to a light module for a lighting device used in vehicles, the light module having at least one light-emitting device and a light conductor, the light conductor being adapted and defined for guiding a beam originating from the light-emitting device and coupled into the light conductor to a light-emitting surface of the light conductor. The invention also relates to a lighting device and a method for reducing color desaturation in a light module, preferably used in lighting devices, especially in vehicles. Background Technology

[0002] Lighting devices for vehicles are already known from existing technology. Typically, lighting devices for vehicles fulfill at least one light-emitting function.

[0003] Here, the light-emitting function can be selected from the following group of light-emitting functions based on the design scheme of the lighting device (e.g., as a headlight and / or as a signal light, such as a brake light, side marker light, driving direction indicator light and / or as a taillight and / or as a daytime running light). The group of light-emitting functions includes (e.g., lane area) lighting functions, such as a repeating flashing light function for indicating the driving direction, a brake light function for indicating braking action, a outline light function for ensuring the visibility of the vehicle during the day and / or at night, such as a taillight function, and combinations thereof.

[0004] A light module for a motor vehicle is known from the applicant's prior art, having a planar light body and a light-emitting device, wherein a beam of light from the light-emitting device can be coupled into the light body and the light body emits light outward via a light-emitting surface. Furthermore, a rear side opposite the light-emitting surface is covered by a reflective or diffuse backscattering covering formed of a frame-like component.

[0005] Currently, in light modules known from existing technology, color desaturation of the white taillight elements can be observed behind a transparent lens during the day. For example, color desaturation occurs in 3D LED taillights, such as in the taillight and driving direction display surfaces, as seen in the applicant's prior art.

[0006] As a solution to avoid color desaturation, it is known from the prior art to utilize tinted lenses to achieve monochromatic light functionality. However, the drawback here is that it cannot achieve multi-color dual functionality.

[0007] However, altering the color and surface structure of the entire back wall to eliminate this drawback disadvantageously leads to limitations in uniformity or luminous efficiency. The use of planar light guides without a back wall, in turn, results in the disadvantage of intensity superposition of successively arranged elements. Summary of the Invention

[0008] The technical problem to be solved by the present invention is to overcome the disadvantages known from the prior art and to provide an optical module, an illumination device and a method for reducing color desaturation in the optical module, wherein the optical module, illumination device and method are preferably used for illumination devices, especially for vehicles, wherein the optical module, illumination device and method achieve a reduction in color desaturation and thus provide an improvement in luminous function, especially during the day.

[0009] According to the present invention, this technical problem is solved by an optical module for a lighting device for a vehicle and a method for reducing color desaturation in the optical module for a lighting device for a vehicle.

[0010] In the light module of the lighting device, especially the lighting device for vehicles, according to the invention, having at least one light-emitting device and a light conductor, the light conductor is adapted and defined for guiding rays originating from the light-emitting device and coupled into the light conductor to the light-emitting surface of the light conductor (especially for emitting rays from the light conductor).

[0011] According to the invention, the optical module has at least one rear wall device, which is preferably arranged at least partially in the optical path of ambient rays incident on the optical conductor from the outside through the light emitting surface of the optical conductor. Preferably, the light emitting surface is a substantially flat (side) surface of the optical conductor.

[0012] According to the invention, the rear wall device (particularly on the side facing the light body) has at least one first rear wall region and at least one second rear wall region, wherein the at least one first rear wall region and the at least one second rear wall region differ from each other, particularly in terms of the reflection and / or absorption characteristics of ambient rays (or ambient rays incident on the light conductor from the outside through the light exit surface).

[0013] In other words, a rear wall device is proposed, which has at least two rear wall regions on its side facing the light conductor, the rear wall regions being different from each other in terms of their reflection and / or absorption characteristics (especially for ambient rays incident on the light conductor and on the rear wall device).

[0014] The advantage of having different back wall regions (which differ from one another, particularly in their absorption and / or reflection characteristics with respect to (ambient) rays) is that it is possible to simultaneously combine the good uniformity of the visible angle over a wide range of, for example, rough, bright (white) back wall regions with colored or reflective back wall regions (which advantageously reduce color desaturation).

[0015] Advantageously, by means of at least one first and second rear wall regions that differ in their reflection and / or absorption characteristics, the advantages of a rear wall region with high reflection and / or low absorption can be combined with the advantages of a rear wall region with low reflection and / or high absorption (which can advantageously ensure reduced color desaturation).

[0016] Advantageously, by using at least one first and second rear wall regions according to the invention, the color desaturation of the externally illuminated optical surface can be reduced while optimally satisfying the desired light-emitting function.

[0017] Preferably, at least one first rear wall region and / or at least one second rear wall region are arranged in the optical path of ambient rays incident on the optical conductor from the outside through the light emitting side (or light emitting surface) of the optical conductor.

[0018] Preferably, the at least one first rear wall region is designed and preferably selected in such a way that the absorption and / or reflection characteristics, particularly caused by the absorption and / or (diffuse) scattering or reflection of rays incident on the first rear wall region, are such that the spectrum of the rays emitted from the light emitting surface substantially corresponds to and / or only slightly deviates from the spectrum of the rays emitted from the light emitting surface, coupled into the photoconductor from at least one light-emitting device. This slight deviation is particularly understood to mean that the difference is (substantially) imperceptible to the user of the light-emitting function or that the difference is within a (preferably pre-given) tolerance.

[0019] However, it is also conceivable that at least one first rear wall region is coordinated with the light-emitting function (e.g., outputting light of a predetermined spectrum) to be satisfied by the optical module, such that the at least one first rear wall region is adapted and determined to selectively absorb (and / or reflect) rays incident on at least one first rear wall region according to a predetermined or to-be-output spectral wavelength.

[0020] For example, the first rear wall region may have a colored or reflective (surface) area. Preferably, the color of the rear wall region is matched to the spectrum to be output by the optical module and / or the light emission function to be satisfied by the optical module. Preferably, the first rear wall region has the color of the rays to be output by the optical module.

[0021] Preferably, the at least one second rear wall region is designed, and preferably selected, in such a way as to achieve (particularly the best possible) uniformity and / or (the greatest possible) luminous efficiency and / or (the highest possible) intensity of the rays emitted from the light-emitting surface, particularly through the reflection of rays incident on the second rear wall region. For example, for this purpose, at least one second rear wall region may have a bright, particularly white, and / or (relatively) rough surface.

[0022] A rough surface is preferably understood as a non-mirror surface, on which rays incident on the surface are diffusely reflected.

[0023] Reflection characteristics should be understood in particular as parameters characterizing the reflection and / or backscattering of incident rays, such as reflectivity. Specifically, the term "reflection" refers not only to directional (specular) reflection but also to diffuse reflection or rays scattered (particularly non-directional or diffuse) on a surface. Preferably, the reflection characteristics herein relate to at least one segment of at least the first or second rear wall region, and particularly preferably to the entire first or second rear wall region.

[0024] Absorption characteristics should be understood in particular as parameters characterizing the absorption of incident rays, such as absorptivity. Here, absorption characteristics preferably relate to at least one segment of at least the first or second rear wall region, and particularly preferably to the entire first or second rear wall region.

[0025] The absorption and / or reflection characteristics may refer here to the light emitting surface (and / or particularly to the fictitious plane formed by the light emitting surface and / or the fictitious plane parallel to the light emitting surface) and the ambient rays that thus enter from the outside (and enter onto the corresponding at least the first or second rear wall region).

[0026] Preferably, (in other words) the absorption characteristics (and similarly the reflection characteristics) can be parameters that characterize the absorption of (ambient) rays incident from the outside into the light conductor through the light emitting surface (which touch the corresponding (at least first or second) rear wall region) by the corresponding (at least first or second) rear wall region.

[0027] For example, at least the first rear wall region (at least partially and preferably substantially over the entire rear wall region) may have an absorptivity and / or reflectivity different from that of at least the second rear wall region.

[0028] Preferably, at least the first rear wall region has at least partially and preferably throughout its respective entire region a substantially uniform and / or identical reflectivity and / or absorptivity. Preferably, at least the second rear wall region has at least partially and preferably throughout its respective entire region a substantially uniform and / or identical reflectivity and / or absorptivity.

[0029] Preferably, at least the first rear wall region and at least the second rear wall region each have (substantially) uniform configuration and / or structure and / or surface properties and / or (surface) structure and / or color on their respective (surface) regions.

[0030] Preferably, the light body is a planar light body. A planar light body is particularly understood as a light body whose (geometric) dimensions are significantly (preferably by at least a multiple of 3, preferably by at least a multiple of 4, preferably by at least a factor and particularly preferably by at least a multiple of 5) larger in two of the three spatial directions than in the third spatial direction.

[0031] Preferably, the optical module is designed and / or the light-emitting device is arranged such that rays emitted from the light-emitting device can be coupled into or coupled into the light conductor via the side of the light conductor (light incident side), and the rays coupled into the light conductor are guided to the light emitting side of the light conductor and, in particular, to the light emitting surface (through the light conductor). Preferably, the light emitting side of the light conductor has a light emitting surface, or particularly preferably, the light emitting side of the light conductor constitutes (configured as an emitting surface) a light emitting surface.

[0032] Preferably, the optical module and, in particular, the optical conductor have (especially optical) coupling output devices, by means of which rays originating from the light-emitting device, coupled laterally at the light incident side (which particularly relates to the side surface of the optical conductor), are coupled out from the optical conductor, especially (at least one primary ray), via the light emitting surface. Preferably, the coupling output device has a plurality of optical coupling output elements for scattering and / or reflecting light originating from the light-emitting device in the direction of the light emitting surface. The plurality of optical coupling output elements may have a serrated and / or sawtooth-shaped orientation in cross-section. The coupling output device can be formed by extending from the surface of the optical conductor.

[0033] Preferably, the optical conductor is substantially cuboid in shape (wherein, surface structures and / or surface profiles for forming the coupling output device are not particularly considered). Preferably, the light emitting surface and / or light emitting side is surrounded by or (directly) adjacent to the side of the optical body.

[0034] Preferably, when viewed from the light-emitting surface toward the back side of the light conductor opposite to the light-emitting surface, and especially in the direction opposite to the light-emitting surface, the rear wall device is arranged behind the back side, and especially behind the surface of the back side.

[0035] Preferably, the rear wall device at least partially and preferably completely covers the back side of the light conductor (especially the side opposite to the light emitting side and / or light emitting surface of the light conductor). Preferably, the rear wall device (especially in a plane parallel to the extension plane of the back side and / or light emitting surface of the light conductor) extends over the extent of the light conductor (in a cutting plane passing through the light conductor along the light emitting surface and / or the back side or rear side of the light conductor).

[0036] Preferably, no additional (optical) elements are arranged between the rear wall device and the light conductor. In particular, the rear wall device is arranged relative to the light conductor such that (ambient) rays emitted from the light conductor, particularly from the rear side, in particular toward the rear wall device, directly strike the rear wall device, without being scattered and / or reflected beforehand by another optical element.

[0037] It is conceivable that the rear wall device is at least partially adjacent to the light conductor and, in particular, adjacent to the back side (especially the back side face) of the light conductor.

[0038] Preferably, not only the at least first rear wall region but also the at least second rear wall region are arranged on the same element of the rear wall device. However, it is also conceivable that the rear wall device has multiple elements, wherein at least one first rear wall region is arranged on one element, and at least one second rear wall region is arranged on a different element of the rear wall device. Preferably, the rear wall device is designed as a one-piece element.

[0039] Preferably, the optical body is configured as a light conductor, more preferably as a planar light conductor, and preferably has a transmittance (light transmittance) in the range of about 85% to about 95%, more preferably in the range of about 90% to 95%. Particularly preferably, the transmittance is about 92%.

[0040] In an advantageous embodiment, the material of at least the first rear wall region differs from that of at least the second rear wall region in terms of absorption and / or reflection characteristics (preferably at least locally and particularly preferably throughout at least the first and / or second rear wall regions). Preferably, the material of the first rear wall region has different scattering characteristics than the material of the at least second rear wall region. Thus, different regions of the rear wall region can be advantageously achieved through different material selections, said different regions differing from each other in their absorption and / or reflection (and / or scattering) characteristics, and thereby advantageously affect the uniformity and / or luminous efficiency and / or color desaturation and, in particular, the reduction of color desaturation of the optical module in different ways.

[0041] Preferably, the material of the at least one first rear wall region being (at least partially) different from that of the at least one second rear wall region contributes to the different reflection and / or absorption properties of the at least one first rear wall region relative to the at least one second rear wall region, and particularly preferably, the reflection and / or absorption properties are (or only) caused by this.

[0042] In another advantageous embodiment, the surface characteristics of at least the first rear wall region differ from those of at least the second rear wall region (preferably at least partially and particularly preferably over the entire first and / or second rear wall regions). This can also advantageously achieve different effects on the rear wall regions in terms of color desaturation and / or the uniformity and / or intensity of the emitted rays when externally irradiated.

[0043] Preferably, the (at least partially) different surface properties of at least one first rear wall region relative to at least one second rear wall region contribute to the different reflection and / or absorption properties of at least one first rear wall region relative to at least one second rear wall region, and particularly preferably, this (or only) causes this.

[0044] In another advantageous embodiment, at least one first rear wall region differs from at least one second rear wall region, at least partially and preferably over the entire first rear wall region, in its surface geometry, wherein this preferably (and preferably only) results in different reflection and / or absorption characteristics (between at least one first rear wall region and at least one second rear wall region). This can also advantageously achieve different effects on the rear wall regions in terms of color desaturation and / or the uniformity and / or intensity of emitted rays upon external irradiation.

[0045] For example, the at least one first rear wall region (and / or the at least one second rear wall region) may have a surface geometry different from that of a plane. For example, the first rear wall region may have at least one recess and / or at least one curved surface wall and / or at least one recess and / or at least one protrusion.

[0046] Preferably, the surface geometry, different from the plane, is adapted to and determined to absorb or absorb rays incident on the surface geometry (especially rays from the direction of the light conductor and especially (environmental) rays incident through the light exit surface of the light conductor) and / or (due to the geometry) reflect and / or scatter from the surface wall more than once, preferably more than twice, preferably more than three times, preferably more than four times, and particularly preferably more than five times before the surface wall leaves the corresponding rear wall region.

[0047] Preferably, at least one second rear wall region is at least partially and preferably (substantially) flat over the entire second rear wall region, forming or being constructed as a flat surface.

[0048] It is conceivable that at least one first rear wall region is also at least partially and preferably (substantially) flat or designed to be flat over the entire first rear wall region.

[0049] Preferably, at least one first rear wall region and at least one second rear wall region are at least partially and preferably (substantially) flat over the entire first rear wall region or are constructed as flat surfaces. In this case, at least the first rear wall region and at least the second rear wall region differ in their material properties and / or their surface properties, thereby causing, in particular, different reflection and / or absorption properties between them.

[0050] Preferably, the at least one first rear wall region has a surface geometry different from that of a flat surface, and the at least one second rear wall region is designed to be flat or designed to be a flat surface. Preferably, the at least one first rear wall region (especially in this case) has the same material properties as the at least one second rear wall region. It is also possible (especially here) for the surface device having at least a first rear wall region and at least a second rear wall region to be manufactured from the same workpiece and / or in a common (unique) method step.

[0051] Preferably, the first and / or second rear wall regions, designed as planar surfaces, are arranged (substantially) parallel to the light emitting surface of the light conductor and / or parallel to the back or rear side of the light conductor.

[0052] Preferably, at least one first and / or at least one second (especially all) rear wall regions are oriented relative to the light conductor and, in particular, relative to the light emitting surface and / or the back side or back side surface, wherein the orientation preferably (substantially) optimizes (especially at a predetermined angle) the expected absorption and / or reflection of (ambient) rays entering the light conductor through the light emitting surface through the respective rear wall regions.

[0053] Preferably, the side of the rear wall device facing the light conductor and / or the surface of the rear wall device, particularly having at least one first rear wall region and / or at least one second rear wall region, extends substantially along the main extension plane. Preferably, the rear wall device is oriented relative to the light conductor such that the main extension plane is arranged substantially parallel to the light emitting surface and / or the back side and / or back side surface of the light conductor.

[0054] In another advantageous embodiment, the main extension direction of a segment of the first rear wall region (and preferably additionally different from and / or opposite to the previously mentioned segment of the first rear wall region) forms a non-zero angle with the main extension plane of the rear wall device toward the light conductor and / or with the main extension direction of the second rear wall region and / or with the main extension direction of the light emitting surface and / or the back side of the light conductor, preferably between 20° and 80°, preferably between 30° and 70°, preferably between 40° and 60°, preferably between 40° and 50°, and particularly preferably at an angle of (substantially) 45°. Preferably, this segment is a region that is (directly) connected to and / or adjacent to the second rear wall region.

[0055] The advantage provided by this is that rays incident substantially perpendicularly onto the main extension plane facing the light conductor on the rear wall device are not reflected back, i.e., not reflected back in a direction perpendicular to the main extension plane. This advantageously ensures that ambient rays incident substantially perpendicularly onto the main extension plane are not directly coupled into the light conductor (and propagated from there toward the light exit surface) after only one reflection and / or scattering in the rear wall region.

[0056] Preferably, the two segments of the first rear wall region are parallel to each other and / or have surface orientations that are parallel to each other. Preferably, the first mentioned segment, and particularly preferably both mentioned segments, extend into the rear wall device (especially with respect to the main extending plane of the rear wall device toward the light conductor surface).

[0057] In another advantageous embodiment, the main extension direction of the at least one first rear wall region extends obliquely to the main extension plane and forms an angle particularly between 30° and 70°, preferably between 40° and 60°, more preferably between 40° and 50°, and particularly preferably substantially 45° (between the main extension direction of the at least one first rear wall region and the main extension plane). Preferably, when viewed along the direction of the main extension plane, the bottom region of the first rear wall region is arranged closer to the light-emitting device than the opening region of the first rear wall region into which rays enter the first rear wall region, and preferably ahead of the bottom region of the first rear wall region in the direction of incidence of rays incident into the first rear wall region.

[0058] In other words, the incident direction of the primary ray emitted by the light-emitting device forms an acute angle (preferably between 40° and 60°, more preferably between 40° and 50° and particularly preferably substantially 45°) with the first sidewall section of the first rear wall region (facing the light-emitting device) which, when viewed along the incident direction, is arranged behind the second sidewall section of the first rear wall region (away from the light-emitting device).

[0059] This provides the advantage that secondary rays generated by primary rays emitted by the light-emitting device and coupled into the light conductor, which strike the first sidewall section (facing the light-emitting device), are guided and reflected and / or scattered from the first rear wall region, particularly toward the light conductor and particularly toward the light-emitting surface. This improves the optical efficiency of the optical module.

[0060] In another advantageous embodiment, the at least one first rear wall region (particularly at least partially and preferably completely) defines a cavity, which is particularly used to absorb ambient rays incident on the light conductor from the outside through the light exit surface of the light conductor. Preferably, the cavity is open only to one side (preferably towards the light conductor). In other words, the cavity preferably has only one opening through which rays can enter the cavity. The construction and / or boundary of the cavity provides the advantage that ambient rays incident on the cavity are preferably reflected and / or scattered multiple times on the cavity walls before leaving the cavity.

[0061] However, it is also conceivable that the cavity (especially only) is limited in the direction perpendicular to the main extending plane of the rear wall device (especially towards the side facing the light conductor) and / or perpendicular to the light emitting surface of the light conductor. In particular, the cavity may be constructed in an elongated and / or grooved and / or grooved and / or wavy manner, and at least one end (especially the two ends) of the elongated and / or grooved and / or grooved and / or wavy structure is open. Preferably, "elongated" should be understood as the cavity following a trajectory whose length is several times (especially twice, preferably four times, preferably 10 times, preferably 20 times) greater than the cavity's extension in the direction perpendicular to it (especially each).

[0062] Preferably, the cavity (and especially the central axis of the cavity) extends along a (main extension) direction, which forms a non-zero angle with the main extension plane of the rear wall device facing the light body side and / or surface, preferably between 20° and 80°, preferably between 30° and 70°, preferably between 40° and 60°, preferably between 40° and 50°, and particularly preferably between 45°. Preferably, the sidewalls of the cavity extend (substantially) parallel to the central axis of the cavity and / or the main extension direction.

[0063] The 45° angle is particularly advantageous because rays incident perpendicular to the main extension plane (on the side of the rear wall device facing the light body) are scattered and / or reflected by the sidewall of the cavity parallel to the main extension device (formed by the first rear wall region), and (subsequently) further scattered and / or reflected into the cavity by the other sidewall of the cavity in a direction away from the main extension plane and / or the light body.

[0064] In another advantageous embodiment, the at least one first rear wall region has an optical trap and / or forms an optical trap. Preferably, the cavity is configured as an optical trap. The optical trap may have an input section that guides rays to be absorbed by the optical trap and / or absorbed into the cavity. Preferably, the inner surface of the cavity is configured in an absorbing and / or scattering manner. The surface of the input section is preferably reflective, but may also be absorbing and / or scattering.

[0065] The optical trap is preferably a radiation receiving region, which is particularly suitable for and defined for receiving radiation (from the radiation receiving region) in the absence of directional backscattering. Preferably, the optical trap can be understood as a substantially backscatter-free radiation receiving region and / or radiation receiving region for attenuating and / or absorbing undesired (ambient) radiation, said radiation receiving region being constructed and defined for reflecting and / or scattering radiation entering the radiation receiving region at least three times, preferably at least five times, and particularly preferably at least eight times, before it exits the radiation receiving region.

[0066] In another advantageous embodiment, at least the second rear wall region is at least partially (and preferably over the entire rear wall region) covered with an absorbing coating. This provides the advantage that ambient rays (particularly undesirable) reaching at least the second rear wall region are absorbed by the absorbing coating (at least partially and preferably corresponding to the absorbency of the absorbing coating).

[0067] Preferably, the absorbing coating has nanoparticles and / or microparticles that are adapted and defined for absorbing (undesirable, especially visible to humans) radiation. For example, the absorbing coating may have carbon nanotubes (also known as CNTs) for absorbing radiation.

[0068] In another advantageous embodiment, at least the second rear wall region comprises nanomaterials, particularly nanomaterials with oriented structures, for absorbing incident ambient radiation.

[0069] In another advantageous embodiment, the rear wall device has a plurality of, particularly similar and preferably identical, first rear wall regions and / or a plurality of, particularly similar and preferably identical, second rear wall regions. The advantage of providing a plurality of first rear wall regions and / or a plurality of second rear wall regions is that more uniform emission can be achieved.

[0070] Preferably, each of the plurality of first rear wall regions is constructed according to the embodiments described (in particular above) within the scope of at least one first rear wall region. Preferably, each of the plurality of first rear wall regions is constructed corresponding to the same embodiments (in particular above) described within the scope of at least one first rear wall region.

[0071] By setting multiple first rear wall regions and / or multiple second rear wall regions, the (existing) rear wall can preferably be structured to minimize color desaturation.

[0072] Furthermore, the proposed optical module is a scalable solution, which can be scaled with respect to the area of ​​the rear wall. Additionally, the proposed optical module offers a suitable volume for manufacturing while maintaining low production costs.

[0073] Preferably, each of the plurality of second rear wall regions is constructed according to the embodiment described (in particular above) within the scope of at least one second rear wall region. Preferably, each of the plurality of second rear wall regions is constructed corresponding to the same embodiment (in particular above) described within the scope of at least one second rear wall region.

[0074] Preferably, all of the first rear wall regions and / or multiple second rear wall regions, and more preferably all of the first rear wall regions have the same extension and / or the same area relative to the main extension plane and / or cross-section.

[0075] In another advantageous embodiment, the plurality of first rear wall regions, particularly those of the same type, and / or the plurality of second rear wall regions, particularly of the same type, are arranged periodically. This provides the advantage of regular light emission through the optical module.

[0076] Preferably, the plurality of first rear wall regions and the plurality of second rear wall regions are arranged in an alternating sequence. This advantageously induces uniform light emission through the optical module. Preferably, in each case, the first rear wall region is (directly) adjacent to and / or surrounded by only the second rear wall region. Alternatively, it is also possible that each second rear wall region is (directly) adjacent to and / or surrounded by only the first rear wall region.

[0077] In another advantageous embodiment, the plurality of first rear wall regions, particularly those of the same kind, and / or the plurality of second rear wall regions, particularly those of the same kind, are arranged in a strip and / or grid and / or lattice and / or checkerboard pattern. It is also conceivable that the plurality of first rear wall regions (respectively) are arranged row by row (or along a diagonal) and / or the plurality of second rear wall regions (respectively) are arranged row by row (or along a diagonal).

[0078] Preferably, at least one first rear wall region and preferably multiple, particularly similar and / or identical, first rear wall regions and / or at least one second rear wall region, and preferably multiple, particularly similar and / or identical, second rear wall regions are arranged in a regular pattern and / or (geometric) shape. Advantageously, areas with different absorption and / or reflection are implemented in patterns or geometries to achieve an attractive design appearance or a better perceptible design appearance that supports contours and / or luminous functions.

[0079] Preferably, the at least one first rear wall region and preferably the plurality of particularly similar and / or identical first rear wall regions and / or the at least one second rear wall region and preferably the plurality of particularly similar and / or identical second rear wall regions constitute the (particularly geometric) structure of the rear wall device, preferably having predetermined structural dimensions. Here, the structural dimensions can preferably be predetermined and given by the geometric dimensions of the first and / or second rear wall regions (and corresponding to arrangements by integer multiples of these respective geometric dimensions). The structural dimensions can preferably be influenced by selecting the dimensions of the first and / or second rear wall regions and / or by arranging identical or similar (first or second) rear wall regions side-by-side.

[0080] Preferably, the side and / or surface (facing the light conductor) of the rear wall device (at least partially and preferably substantially throughout) is composed of at least one first rear wall region and / or at least one second rear wall region, and preferably a plurality of first rear wall regions and / or a plurality of second rear wall regions.

[0081] Preferably, the area formed by at least one first rear wall region (and preferably by multiple first rear wall regions) and / or by at least one second rear wall region (and preferably by multiple second rear wall regions) covers the area arranged in the optical path and, in particular, in multiple (especially possible) optical paths of ambient rays (which enter the light conductor from the outside through the light exit surface and, in particular, turn towards the rear wall device from the light conductor).

[0082] Preferably, the first rear wall region (especially each one) absorbs a higher (especially relatively, i.e., the corresponding cross-sectional area of ​​the reference rear wall device is parallel to the main extension plane) share of the (pre-defined) ambient rays irradiating the respective rear wall region than the second rear wall regions (arranged in the same location and having the same area). Preferably, the second rear wall region can be given by a rough, bright, and especially white rear wall region, while the first rear wall region can be given by, for example, a colored or reflective region and / or a region with a light trap.

[0083] Preferably, the ratio of the cross-sectional area of ​​the entire number of first rear wall regions (particularly described in more detail in the preceding paragraph) to the cross-sectional area of ​​the entire number of second rear wall regions (particularly described in more detail in the preceding paragraph) is in the range of 1:20 to 20:1, preferably in the range of 1:10 to 10:1, preferably in the range of 1:5 to 5:1, preferably in the range of 1:3 to 3:1, preferably in the range of 1:2 to 2:1, particularly preferably in the range of 0.8 to 1.2, and particularly preferably (substantially) about 1. Here, the corresponding cross-section particularly relates to a section passing through the corresponding rear wall region along a plane parallel to the main extending plane on the light-facing side of the rear wall device and / or to a section passing through the corresponding rear wall region along a plane parallel to the light-emitting side and / or the back side of the light body. By selecting the cross-sectional area ratio, a suitable trade-off can preferably be set between reduced color desaturation and a wide or good uniformity of the visible angle and / or luminous efficiency.

[0084] Preferably, the ratio of the cross-sectional area of ​​the entire first rear wall region to the cross-sectional area of ​​the entire second rear wall region is in the range of 1:20 to 1, more preferably in the range of 1:10 to 1, more preferably in the range of 1:5 to 1, more preferably in the range of 1:4 to 1, more preferably in the range of 1:3 to 1, more preferably in the range of 1:2 to 1, and especially in the range of 1.5 to 1. Therefore, in such a design, the focus is preferably placed on a large area of ​​light output and / or good uniformity / visible angle (e.g., a rough, bright (especially white) rear wall region).

[0085] Preferably, the ratio of the cross-sectional area of ​​all first rear wall regions to the cross-sectional area of ​​all second rear wall regions is in the range of 1 to 20:1, more preferably in the range of 1 to 10:1, more preferably in the range of 1 to 5:1, more preferably in the range of 1 to 4:1, more preferably in the range of 3 to 3:1, more preferably in the range of 2 to 2:1, and particularly in the range of 1 to 1.5. Therefore, in this design, the preferred focus is on reducing color desaturation.

[0086] Preferably, the optical module has a rear wall device microstructured, particularly by a plurality of first and / or second rear wall regions, wherein, preferably, the first rear wall regions (in particular, respectively) have and / or constitute an optical trap and / or a cavity.

[0087] Preferably, the optical modules (particularly preferably in the case of a microstructured rear wall device and / or in embodiments where the first rear wall region (especially respectively) has and / or is constructed and / or defines an optical trap and / or cavity) have more than 10, preferably more than 50, preferably more than 100, preferably more than 500, and particularly preferably more than 1,000 first and / or second rear wall regions.

[0088] Preferably, (especially each) first rear wall region (which particularly preferably has and / or constructs and / or defines a light trap and / or cavity) and / or (especially each) second rear wall region extend (geometrically) in at least one direction (and preferably in two mutually perpendicular directions respectively) along a cross section (which is parallel to the main extension plane of the rear wall device toward the side or face of the light body and / or parallel to the plane of the light emission side and / or the plane of the back side of the light body) in the range of 50 μm to 1 cm, preferably in the range of 75 μm to 5 mm, preferably in the range of 100 μm to 3 mm, preferably in the range of 100 μm to 1 mm, and particularly preferably in the range of 200 μm to 500 μm.

[0089] Preferably, the optical module (particularly preferably in one embodiment, the first rear wall region and the second rear wall region differ, especially only in their material properties and / or surface properties, and particularly causing different absorption and / or reflection properties between the first and second rear wall regions) has at least 1, preferably at least 2, preferably at least 3, preferably at least 5 and / or at most 10, preferably at most 5, preferably at most 4, preferably at most 3, preferably at most 2, and particularly preferably exactly one first and / or second rear wall region.

[0090] Preferably, (particularly preferably in one embodiment of the optical module, wherein the first rear wall region is distinguished from the second rear wall region, particularly by means of material properties and / or surface properties, and thereby resulting in different absorption and / or reflection characteristics between the first and second rear wall regions), (particularly each) first rear wall region and / or (particularly each) second rear wall region extends (geometrically) in at least one direction (and preferably in two mutually perpendicular directions), along a cross-section (which is parallel to the main extension plane of the rear wall device toward the side or face of the light body and / or parallel to the plane of the light emitting side and / or the plane of the back side of the light body) in the range of 1 mm to 30 cm, preferably in the range of 5 mm to 20 cm, preferably in the range of 1 cm to 10 cm, and particularly preferably in the range of 3 cm to 8 cm.

[0091] Alternatively, the first and / or second rear wall regions may extend substantially over the entire rear wall device (on the side facing the light body) and surround at least one, and preferably multiple, corresponding additional (i.e., second or first) rear wall regions and encircle these rear wall regions.

[0092] Alternatively, the first (or alternatively the second) rear wall region may extend along the outer contour of the optical module and / or the rear wall region and / or substantially at least segmentally follow the contour line of the optical module. Preferably (especially in this embodiment), only the second (or correspondingly the first of the above alternatives) rear wall region is arranged in the central and / or internal region of the optical module and / or the rear wall device (with respect to the cross-sectional plane of the main extension device parallel to the rear wall device).

[0093] It is possible to set exactly one first rear wall region and exactly one second rear wall region.

[0094] In another advantageous embodiment, the rear wall device is an injection-molded part. Preferably, the rear wall device is integral and / or one-piece. Preferably, the rear wall device is made of polycarbonate, and particularly preferably, the rear wall device is made of polycarbonate.

[0095] Preferably, the first and second rear wall regions (particularly preferred in one embodiment of the optical module, wherein the first and second rear wall regions differ, particularly only in their material properties and / or surface properties, and thereby cause different absorption and / or reflection properties between the first and second rear wall regions) are manufactured in at least one different (particularly injection molding) manufacturing step (e.g., sequentially followed in time and / or under different pressures) and / or from materials different in at least one component. Thus, for example, the first rear wall region may be or be made of (particularly black) colored plastic, while the second rear wall region may be or be made of plastic colored in a light color, particularly white.

[0096] Preferably, at least one first (or alternatively second) and preferably all first (or alternatively second) rear wall regions are first cast or manufactured in a first injection molding process step, and at least one second (or alternatively first according to the above) and preferably all second (or alternatively first) rear wall regions are cast or manufactured in a second (particularly temporally subsequent) injection molding process step (using a different material than that used in the first injection molding process step).

[0097] Preferably, at least one focusing optics (or collimating optics) is arranged between the at least one light-emitting device and the sidewall of the light conductor (in which the rays of the light-emitting device are coupled or coupled and / or are capable of coupling). Preferably, the focusing optics (or collimating optics) is adapted and determined to collect or “capture” light from the light rays of the light source at angles up to 180° and, in particular, couple it into the light conductor.

[0098] Preferably, the light-emitting device is an electrically operable light source, which is preferably mounted on at least one light-incident side of the light body. The light-emitting device is preferably configured to emit monochromatic light, particularly as an LED (LED = Light Emitting Diode), or (particularly RGB) LED, for emitting particularly multi-colored and / or white light and / or any color light. Preferably, the optical module has at least one, and preferably multiple, light-emitting devices configured as LEDs. Preferably, the optical module has a circuit board and / or a printed circuit board (PCB), on which the light-emitting devices and preferably light conductors and / or back wall devices are arranged.

[0099] Preferably, the optical conductor is understood as an object adapted and defined for guiding (primary) rays coupled into the optical conductor, the (primary) rays propagating in a first region of the optical conductor along an optical path extending in a first direction, such that the coupled (primary) rays propagate in a second region of the optical conductor (particularly different from the first region) along an optical path extending in a second direction. Here, in particular, the first direction differs from the second direction (and preferably forms a non-zero angle and / or is inclined to each other).

[0100] Here, the first region can be the region where the light rays are coupled into the optical conductor and / or the second region can be the region where the light rays are coupled out of the optical conductor (i.e., particularly including at least a localized portion of the light-emitting side). The propagation of the rays can be achieved, for example, by a coupling output device (coupling output optics).

[0101] Furthermore, the present invention relates to an alternative embodiment of an optical module, preferably for lighting equipment, particularly for vehicles, in which an OLED (Organic Light Emitting Diode) is used (at least and preferably exactly) as the light-emitting device. Specifically, in the case of an OLED, the generated rays extend linearly or orthogonally to the layer structure of the emitting rays within the OLED structure. The emitted rays (particularly those generated in the stack of organic layers) then pass through a glass substrate or polymer layer.

[0102] In this case, the light conductor is preferably an object (preferably designed as a glass substrate and / or polymer layer) in which the light path of the rays generated (in particular by OLED) extends substantially linearly throughout the entire light conductor and / or from its entrance region into the light conductor to its exit region from the light conductor.

[0103] In particular, the optical conductor is preferably an object in which rays coupled into the optical conductor (in essence) propagate along a propagation direction or a light path that extends in essence until they are coupled out of the optical conductor (and / or until the light exits).

[0104] Preferably, this embodiment of the optical module has at least one (and preferably exactly one) light-emitting device designed as an OLED and a light conductor, the light conductor being adapted and defined for guiding or transmitting rays originating from the light-emitting device and coupled into the light conductor to the light-emitting surface of the light conductor.

[0105] Preferably, the light incident side of the light conductor is arranged on the side of the light conductor opposite to the light emitting side, and the rays emitted from the light-emitting device are coupled into the light conductor.

[0106] Preferably, (in this embodiment) the light conductor is a particularly (clearly) transparent (outer) lens.

[0107] Preferably, this embodiment of the optical module has at least one rear wall device, which is at least partially arranged in the optical path of ambient rays incident from the outside through the light emitting side of the optical conductor into the optical conductor.

[0108] According to the invention, the rear wall device has at least one first rear wall region and at least one second rear wall region, wherein the at least one first rear wall region and the at least one second rear wall region differ from each other, particularly in terms of reflection and / or absorption characteristics of ambient radiation. Here, the rear wall device can possess, individually or in combination with each other, all the features described above within the scope of the optical module.

[0109] The proposed (alternative) implementation offers the advantage that, for example, multi-color OLEDs (e.g., red / yellow) may also suffer from color desaturation (as described above) behind a clear, transparent outer lens (especially under external (daytime) illumination). The use of a back wall, as proposed above, can also be considered (particularly in a similar manner) in the case of (e.g., transparent) OLEDs.

[0110] Preferably, the OLED is a multicolor OLED (which, for example, emits red and / or yellow light).

[0111] Preferably, the OLED is a transparent OLED. Particularly preferably, the back wall device here is a structured back wall device and / or back wall (device) in which at least one first back wall region differs from at least one second back wall region at least partially and preferably over the entire first back wall region by means of different surface geometry, and thereby causes different reflection and / or absorption characteristics.

[0112] Alternatively, it is conceivable that the OLED (especially the opaque one) has a back wall (especially generated within the scope of the OLED manufacturing process), said back wall having at least a first back wall region and at least a second back wall region. Here, the OLED itself constitutes a back wall device and / or is materially locked to the back wall device. For example, a structured back wall device can be implemented within the scope of the OLED manufacturing process by masking and / or evaporating (different) sub-regions.

[0113] The present invention also relates to a lighting device, preferably a lamp, especially a taillight and / or a driving direction indicator (or turn signal), and / or a lighting device for external and / or internal lighting of a vehicle, preferably for fulfilling at least one (described at the beginning) luminous function of the vehicle.

[0114] According to the present invention, the lighting device includes at least one optical module and preferably includes multiple optical modules according to at least one of the embodiments described above. Preferably, the multiple optical modules are provided as an optical unit, in which the multiple optical modules are connected to each other in one piece. Furthermore, the optical modules may be arranged and / or fixed on a common circuit board, which also carries light-emitting devices associated with the light source.

[0115] Preferably, the lighting device is a vehicle light, especially a taillight or a driving direction indicator (especially a turn signal). Preferably, the lighting device is a lighting device for external lighting and / or internal lighting.

[0116] The present invention also relates to a means of transportation (or vehicle), particularly a motor vehicle, having at least one lighting device according to the above embodiments, and preferably at least two lighting devices according to the above embodiments. The means of transportation may, in particular, be a (motorized) road vehicle.

[0117] The present invention also relates to a method for reducing, preferably for suppressing, color desaturation in light modules, particularly in lighting devices for vehicles, where the color desaturation occurs under the influence of ambient radiation, particularly when the light module is irradiated by ambient radiation (from the outside), especially when the light module is used to perform its light-emitting function.

[0118] Here, the optical module has at least one light-emitting device and preferably a light conductor in order to realize the light-emitting function. The light conductor is adapted and defined for guiding rays originating from the light-emitting device and coupled into the light conductor to the light-emitting surface of the light conductor, and in particular for emitting from the light conductor.

[0119] Preferably, the at least one light-emitting device emits rays, which are preferably (especially by means of a coupling-injection optics) coupled into the light conductor and preferably guided to the light-emitting surface of the light conductor via a coupling-out device (especially a coupling-out optics) and / or a light-guiding device, wherein the rays are emitted from the light conductor, especially at the light-emitting surface.

[0120] The optical module also has at least one rear wall device, which is at least partially arranged in the optical path of ambient rays incident from the outside, preferably through the light emitting surface of the optical conductor, into the optical conductor and / or the optical module.

[0121] According to the present invention, the rear wall device has at least one first rear wall region and at least one second rear wall region.

[0122] Here, the ambient rays are absorbed and / or reflected by the at least one first rear wall region and the at least one second rear wall region with different intensities.

[0123] Different intensities of absorption and / or reflection are particularly understood to mean that, through at least one first rear wall region compared to at least one second rear wall region (especially in the case of the same irradiation by (ambient) rays and preferably substantially over the corresponding entire rear wall region), different proportions of incident (ambient) rays are absorbed and / or reflected and / or backscattered and / or back-reflected directionally toward the light conductor.

[0124] Different intensities of absorption and / or reflection are preferably caused by different absorption and / or reflection characteristics of at least one first rear wall region relative to at least one second rear wall region.

[0125] Therefore, within the scope of the method, it is also proposed to structure the (existing) back wall to minimize color desaturation. For example, different absorption and / or reflection (first and / or second) (back wall) areas can be created through different colors or surface properties. Advantageously, these areas are implemented as patterns or geometries to advantageously achieve an attractive design appearance. The good uniformity of the visible angle over a large area of ​​a rough, bright (preferably white) back wall is advantageously combined with reduced color desaturation in colored or reflective areas.

[0126] Furthermore, advantageously, the pattern, shape, color, and / or reflectivity and / or structural dimensions can be varied for different implementations.

[0127] The present invention also relates to a method for operating a lighting device according to one of the above embodiments, particularly preferably a headlight or light source for a vehicle, to satisfy the luminous function of the vehicle.

[0128] Preferably, the optical module described above is configured, adapted, and / or determined to implement, individually or in combination with each other, a method for reducing color desaturation and all the method steps already described above in conjunction with the method. Conversely, the method can be equipped, individually or in combination with each other, with all the features described within the scope of the optical module.

[0129] The means of transport described above can be motor vehicles, particularly those controlled by a driver (“driver-only”), semi-autonomous, autonomous (e.g., Level 3, 4, or 5 autonomy (standard SAE J3016)), or self-driving motor vehicles. Level 5 autonomy here refers to a fully automated means of transport. The means of transport can also be driverless transport systems. Here, the means of transport can be controlled by a driver or drive autonomously.

[0130] In addition to road vehicles, vehicles can also be flying taxis, airplanes and other vehicles or other types of vehicles, such as air vehicles, water vehicles (e.g., ships) or rail vehicles.

[0131] The invention of the optical module and lighting device for a vehicle has been described in conjunction with transportation vehicles. However, the invention is also applicable to other optical modules, lighting devices, or lighting systems, for example in the fields of general transportation (aircraft manufacturing, rail transportation, shipbuilding), general lighting, advertising lighting, or consumer electronics, and / or to light-emitting functions (e.g., illumination and / or lighting) to be realized from these fields. The applicant reserves the right to claim protection for an optical module for use in a lighting device from one of the said areas and / or for the application or operation of the described optical module or lighting device. Attached Figure Description

[0132] Further advantages and implementation methods are illustrated in the accompanying drawings, wherein the same reference numerals denote the same or equivalent elements. In the drawings:

[0133] Figures 1a to 1d A comparison diagram of vehicle lights operating at night and during the day, based on existing technology, is shown;

[0134] Figures 2a to 2b Front views of a rear wall device of an optical module according to one embodiment of the invention are shown respectively;

[0135] Figure 3 A schematic cross-sectional view of an optical module according to the invention, based on one embodiment, is shown.

[0136] Figure 4 Shown in Figure 3 A partial detail view of the optical module according to the present invention is shown in the figure;

[0137] Figure 5a , 5b A front view and a rear view of a vehicle lamp according to another embodiment of the invention are shown;

[0138] Figure 6 A schematic cross-sectional view of an optical module according to another embodiment of the invention is shown;

[0139] Figure 7 Shown in Figure 6 A partial detail view of the optical module according to the present invention is shown in the figure;

[0140] Figure 8a , 8b A front view and a rear view of a vehicle lamp according to another embodiment of the invention are shown;

[0141] Figure 9 A schematic cross-sectional view of an optical module according to another embodiment of the invention is shown;

[0142] Figure 10 Shown in Figure 9 A partial detail view of the optical module according to the present invention is shown in the figure;

[0143] Figure 11a , 11b A front view and a rear view of a vehicle lamp according to another embodiment of the invention are shown;

[0144] Figure 12 A schematic cross-sectional view of an optical module according to another embodiment of the invention is shown;

[0145] Figure 13 Shown in Figure 12 A partial detail view of the optical module according to the present invention is shown in the figure;

[0146] Figure 14 Three views are shown of a taillight with a rear wall featuring a different design.

[0147] Figure 15 Three views are shown of turn signals with different rear wall patterns.

[0148] Figures 16 to 19 Diagrams illustrating the theory of color desaturation at dusk or during the day; and

[0149] Figure 20 A vehicle with an optical module according to the present invention is shown. Detailed Implementation

[0150] Figure 1a and 1b A taillight 12a that operates at night according to the prior art is shown. Figure 1a ) and taillight 12a that operates during the day under the influence of ambient radiation ( ) Figure 1b (Comparison diagrams shown in top views on the light-emitting surface, the light-emitting surface, or the glass of the headlights, respectively.) As another example, Figure 1c The diagram shows a driving direction indicator 14 that operates at night according to the prior art, and in contrast, a driving direction indicator 14 that operates during the day (under the influence of ambient rays) is shown (a top view of the glass of the light-emitting surface or the light-emitting surface or the headlight, respectively).

[0151] from Figure 1a and Figure 1b The corresponding view and Figure 1c and 1d As can be seen from the corresponding comparison of the views, vehicle lights 12a and 14 have a richer hue or output a richer hue at night (and therefore without the influence of ambient rays or without external illumination of the vehicle lights by means of ambient rays) than during the day (with the influence of ambient rays or by means of external illumination of the vehicle lights by means of ambient rays).

[0152] Figures 1a to 1d The diagram illustrates the (undesirable) color desaturation that occurs during the day behind a transparent lens in, for example, a white taillight element according to the prior art, and in, for example, a 3D-LED taillight.

[0153] Figure 16-19 A diagram is shown to illustrate the theory of color desaturation at dusk or during the day.

[0154] Figure 16 This demonstrates the nighttime transmittance. An LED spectrum 94 is generated, with rays L coupled into a white diffuse glass plate 96 and emitted as light emission LE on the side of the glass plate 96 facing the external environment. The emitted rays are perceptible to an observer 100.

[0155] When an observer observes the side of glass plate 96 facing the external environment, they essentially perceive... Figure 18 The LED spectrum 94 shown in the image, its perceived color (e.g., in the image of the taillight 12a at night) is in Figure 18 The color space 102 is shown as a crosshair indicated by arrow P1.

[0156] Figure 17 The corresponding conditions are shown for daytime or dusk. During daytime or dusk, observer 100 takes the superposition of light LE transmitted through a white diffused glass plate and ambient rays TE, the light having an LED spectrum 94, and the ambient rays T obtained after reflection from the ambient rays T incident on the white diffused glass plate 96 according to the sunlight spectrum 98. The perceived spectrum corresponds to the superposition of the LED spectrum 94 and the sunlight spectrum 98 and is obtained in… Figure 19 The spectrum 104 is shown in the figure. Another perceived color is obtained by superimposing the LED spectrum and the sunlight spectrum, and this other perceived color is desaturated compared to the single LED spectrum (see [reference]). Figure 12 b). This desaturation is illustrated in color space 102 by the color value marked with arrow P2, which is obtained by the transmission of LED rays and the reflection of sunlight rays.

[0157] Figure 3 The diagram shows an optical module 10 according to one embodiment of the invention, here a schematic cross-sectional view of a surface light conductor with a beam trap. Reference numeral 24 here denotes a light conductor with a coupling output optics (or coupling output device), which is here a surface light conductor. LEDs 19 or more LEDs arranged on a printed circuit board 26 emit rays (particularly via coupling input optics) that are coupled into the light conductor 24 and guided via the coupling output optics to the light exit surface A of the light conductor 24, through which the (primary) rays exit the light conductor.

[0158] exist Figure 3 The embodiment shown also includes a rear wall device 20 configured as (here, it is constructed as a single piece) a rear wall. Reference numeral 28 indicates a light-shielding plate or frame, which is arranged here on the light-emitting side of the light conductor (which has a light-emitting surface A) in the outer edge region of the light conductor.

[0159] Reference numeral E indicates the orientation of the main extension plane of the rear wall device 20 or rear wall 22, which extends perpendicularly to the plane of the drawing (especially by the dashed line indicated by E) on the side facing the light conductor 24. It preferably (as shown here) extends parallel to the light emitting surface A and / or parallel to the back side of the light conductor 24 opposite to the light emitting surface A.

[0160] Figure 4 Shown in Figure 3 The figure shows a partial detail of the optical module 10 according to the invention. Here, the same reference numerals denote elements that are the same or have the same or similar function.

[0161] The (optical) coupling output device (which has a sawtooth cross-section) formed here by the light conductor 24 (through the surface structure) is constituted by this detailed view. This coupling output device is adapted and determined to deflect the (primary) rays 40 from the light-emitting device (here, the LED) toward the light-emitting surface A, such that the primary rays 42 deflected or scattered toward the light-emitting surface A can be emitted from the light conductor 24 (and from the optical module) via the light-emitting surface A.

[0162] Reference numeral 22 indicates the rear wall (which forms the rear wall device 20) constructed integrally and in one piece (and made of a single material, particularly in a common process step or in a single injection molding process step). The second rear wall region has a second rear wall region 34 on its side facing the light conductor. Four (at least partially shown) second rear wall regions 34 can be seen in the detailed drawing. These second rear wall regions 34 are, here, the reflecting surfaces (of the rear wall). Reference numeral 32 indicates the first rear wall region, which here defines the beam trap or light trap 31. Figure 4 The detailed diagram shows three first rear wall regions 32. All first and second rear wall regions are implemented in the same way and arranged periodically.

[0163] Here, the autonomously extending plane E of the first rear wall region (see...) Figure 3 The first rear wall region 32 extends into the interior of the rear wall. Here, the main extension direction of the first rear wall region 32 and / or at least one segment of the first rear wall region (which preferably extends along the central axis M of the first rear wall region 32) preferably forms an acute angle with the main extension plane E, and here and particularly preferably an angle of 45°, along which the first rear wall region extends into the interior of the optical conductor.

[0164] Preferably, the light trap and / or the first rear wall region is inclined relative to the main extension plane E of the rear wall device 20, such that the bottom region of the first rear wall region 32 is arranged closer to the light-emitting device (here, the light-emitting diode 19) in a direction extending (only) along the main extension plane E than the opening region and / or edge region of the light trap or the first rear wall region 32 (which is adjacent to the second rear wall region 34).

[0165] Such as through Figure 4 The optical path of the ambient ray 44, which passes through the light emitting surface A from the outside and is incident into the light conductor 24, is shown in the figure. The ambient ray is received and absorbed in the light trap 31 formed and / or defined by the first rear wall region 32 (shown through the optical path 45), such that the ambient ray 44 no longer has a directional back reflection away from the light trap 31 (at least in the direction of the light emitting surface A).

[0166] Secondary rays emitted by the light-emitting diode and coupled into the light conductor, which are generated or formed on the coupling output device of the light conductor 24, are reflected (in the direction toward the light conductor) on the reflective surface of the second rear wall region (see secondary LED light path 48) and / or reflected and / or scattered (shown by the light path indicated by reference numeral 46) in the upper region of the light trap or the first rear wall region by the wall side 47 away from the light-emitting device toward the light-emitting surface A of the light conductor, such that the secondary rays are not absorbed in the light trap relative to the light path 48, but advantageously contribute to improving the light intensity and light efficiency of the light module 10.

[0167] Figures 2A and 2B show front views of the rear wall devices 16 and 18 of the optical module 10 according to one embodiment, respectively (where only the rear walls are shown). Here, structured rear walls (with beam traps) can be seen, wherein multiple first and second rear wall regions are arranged periodically or regularly row by row (see Figure 2A). Figure 2a And it is arranged in a chessboard pattern.

[0168] Therefore, in order to suppress external or ambient radiation, it is proposed to periodically structure the existing back wall to create a beam trap and absorb external light. This reduces or avoids color desaturation of the optical surface under external illumination while optimally satisfying the desired light-emitting function.

[0169] Here, the structural dimensions can be varied (for different implementations of the rear wall). Furthermore, additional absorbent coatings and / or layers of nanomaterials with oriented structures can be applied.

[0170] The proposed design provides a scalable solution (in terms of rear wall area) that is characterized by both low production costs and suitable volume manufacturing.

[0171] Figure 6 A schematic cross-sectional view of an optical module 10 according to another embodiment of the invention is shown, the optical module having, in particular, a structured rear wall for a planar light conductor 24. In the embodiment shown here, the first rear wall region 56 is made of a first material, which differs from the second material in the two second rear wall regions 57 and 58. Here, the difference between the first and second materials lies particularly in scattering properties (especially with respect to ambient rays, which are preferably light from the wavelength range of the solar spectrum).

[0172] Figure 7 Shown in Figure 6The figure shows a partial detail of the optical module 10 according to the invention. The different scattering characteristics present at points 51 and 52 are illustrated by the different scattering of the incident ambient ray 44 at points 51 and 52, and are shown here by the scattered rays indicated by reference numeral 53 and reference numeral 54.

[0173] Here, point 51 is a point in the first rear wall region 56 and point 52 is a point on the surface of the second rear wall region 57. The material of the second rear wall region (at and around point 52) ​​is suited to and determined for (relatively) strong scattering, while the material of the first rear wall region is suited to and determined for (relatively) weak scattering of the incident ambient ray 44.

[0174] Figure 5a and 5b A front view 59a of a vehicle lamp according to another embodiment of the invention is shown, and (in...) Figure 5a The nighttime appearance of the headlights shown is 59b. Here it can be seen that a first rear wall region and a second rear wall region are positioned there, forming a light conductor on the rear wall. Here, the second rear wall region, extending along the edge region, is particularly prominent in the nighttime appearance (see...). Figure 5b This results in a higher light intensity emitted by the optical module in this region compared to the other (especially the first) rear wall region, which is essentially located in the central region of the rear wall region (where a relatively small share of the rays incident on it are scattered along the direction of the light exit surface A).

[0175] In the front view 61 of a headlight or light module constructed according to this embodiment, a grid pattern is shown corresponding to the arrangement of the first and second rear wall regions, showing regions with lower intensity 61a and higher light intensity 61b. Similarly, in the nighttime appearance, a grating-shaped region 62a with lower intensity is also obtained, which has a higher light intensity grating-shaped region 62b.

[0176] Figure 8a 8b, 9, and 10 illustrate one embodiment of the optical module according to the invention or a structured back wall for a planar optical conductor corresponding to another embodiment, wherein a plurality of first back wall regions 66 (particularly of a material, e.g., a dark and particularly black material with low scattering) and a plurality of second back wall regions 67 are provided, the first and second back wall regions forming a (particularly grid-like) pattern (see...). Figure 8a ,8b).

[0177] Figure 11a 11b and 12 illustrate one embodiment of the optical module or structured back wall for planar optical conductors according to the invention, wherein the back wall or back wall device 20 is in... Figure 8aThe embodiments shown in 8b and 9 have an inverted pattern. Accordingly, the substrate of the rear wall 22 is made of a dark, especially black, material that forms a first rear wall region 74 on its surface, while a light-colored material (especially white) is arranged in the gaps of the substrate and accordingly forms a plurality of second rear wall regions 73.

[0178] Accordingly, in Figure 11a and 11b The front view 71 and nighttime appearance 72 shown in the figure are obtained with Figure 8a and 8b Compared to the inverted image, a high-intensity grid-like structure 71a or 72a is obtained here, along with low-intensity grid-like aperture regions 71b and 72 located therebetween.

[0179] Similar to Figure 7 , Figure 10 and 13 Shown separately in Figure 9 or Figure 12 The figure shows a detailed view of a portion of an optical module 10 according to the present invention, which corresponds to another embodiment. See also the explanatory notes for these figures. Figure 7 .

[0180] Figure 14 and 15 Show the taillights respectively ( Figure 14 ) or turn signal ( Figure 15 The three views of the diagram show conversion schemes for the rear wall with different patterns. Here, the topmost figures 82 and 88 respectively represent black / white patterns for the structured rear wall used for the planar light conductor; the corresponding middle figures 84 and 90 have inverted patterns compared to the topmost figures 82 and 88, i.e., white / black patterns for the structured rear wall used for the planar light conductor; and the bottommost figures 86 and 92 respectively represent a (pure) white rear wall. The taillights and turn signals here differ from each other through their light-emitting function, particularly through the color values ​​of the emitted (LED) rays. When the taillights are red, the turn signals emit (or emit from the LEDs) orange or yellow light.

[0181] Figure 20 A vehicle 1 is shown with two lighting devices 2 according to the invention, each lighting device having at least one light module 10 according to the invention, and the lighting devices function as taillights. A control unit 5 is adapted to and determines, via signal and control lines S, for operating the lighting devices 2. Here, reference numeral 2a denotes the portion of the lighting device on the vehicle body side, and reference numeral 2b denotes the portion of the lighting device 2 on the rear cover side.

[0182] The applicant reserves the right to claim protection for all features disclosed in the application documents as having inventive substance, provided that they are novel individually or in combination with respect to the prior art. Furthermore, it should be noted that features that may be advantageous in themselves are also described in the various figures. Those skilled in the art will readily recognize that a particular feature described in the figures may also be advantageous without adopting other features in that figure. Moreover, those skilled in the art will recognize that advantages can also be obtained through a combination of multiple features shown in a single or different figures.

[0183] List of reference numerals

[0184] 1. Transportation

[0185] 2 lighting fixtures

[0186] 2. Lighting device on the side of the vehicle body

[0187] 2b Rear cover side portion of the lighting device

[0188] 5 control units

[0189] 10 optical modules

[0190] 12a taillights

[0191] 14. Driving direction indicator

[0192] 19 Light-emitting devices

[0193] 16, 18, 20 rear wall devices

[0194] 22 posterior wall

[0195] 24 photoconductor

[0196] 26 Printed Circuit Boards

[0197] 28 baffles, frame

[0198] 31 beam trap

[0199] 32 First posterior wall region

[0200] 34 Second posterior wall region

[0201] 40 Coupled-injected rays

[0202] 42 scattered primary rays

[0203] 44 Environmental Radiation

[0204] 46 Scattered / Reflected Secondary Rays

[0205] 45 optical paths

[0206] 47. Wall side away from the light source

[0207] 48 secondary rays

[0208] Points on the rear wall surface, 51 and 52

[0209] 53, 54 Scattered Rays

[0210] 56 First posterior wall region

[0211] 57, 58 Second posterior wall region

[0212] 59a Front View

[0213] 59b Nighttime Appearance

[0214] Areas with lower intensity (61a, 62b)

[0215] 61b and 62b are regions with higher light intensity.

[0216] Daytime exterior views of 61 and 71

[0217] 62, 72 Nighttime Appearance

[0218] 71a, 72a high-intensity areas

[0219] 71b, 72b lower intensity areas

[0220] 66 First posterior wall region

[0221] 67 Second posterior wall region

[0222] 73 Second posterior wall region

[0223] 74 First posterior wall region

[0224] 94 LED spectrum

[0225] 102 color space

[0226] 104 superimposed LED spectrum and sunlight spectrum

[0227] 96 White Diffuser

[0228] A light exit surface

[0229] E Main Extension Plane

[0230] K Circle

[0231] M central axis

[0232] LE light emission

[0233] Arrows P1 and P2

[0234] S signal and control lines.

Claims

1. An optical module for a lighting device (2) of a vehicle (1), the optical module having at least one light-emitting device (19) and a planar light conductor (24), the light conductor being adapted and defined for guiding rays (40) originating from the light-emitting device (19) and coupled into the light conductor (24) to a light-emitting surface (A) of the light conductor (24), and the optical module having at least one rear wall device (20) at least partially arranged in the optical path of an ambient ray (44) incident from the outside through the light-emitting surface (A) of the light conductor (24) into the light conductor (24), wherein, The rear wall device (20) has at least one first rear wall region and at least one second rear wall region, wherein the at least one first rear wall region and the at least one second rear wall region differ from each other in terms of reflection and / or absorption characteristics with respect to ambient rays (44), wherein the rear wall device (20) is arranged relative to the light conductor such that rays emitted from the rear side from the light conductor toward the rear wall device directly hit the rear wall device, wherein the first rear wall region is a low-reflection and / or high-absorption rear wall region, and the second rear wall region is a high-reflection and / or low-absorption rear wall region, wherein the at least one first rear wall region differs from the at least one second rear wall region at least partially by means of surface geometry, and thereby causes different reflection and / or absorption characteristics.

2. The optical module according to claim 1, characterized in that, The material of the at least one first rear wall region differs from the material of the at least one second rear wall region in terms of absorption and / or reflection properties.

3. The optical module according to claim 1, characterized in that, The surface characteristics of the at least one first rear wall region are different from the surface characteristics of the at least one second rear wall region.

4. The optical module according to claim 1, characterized in that, The main extension direction of the first rear wall region forms an angle between 20° and 80° with the main extension direction of the second rear wall region and / or with the main extension plane (E) of the rear wall device facing the light conductor.

5. The optical module according to claim 1, characterized in that, The main extension direction of at least one first rear wall region extends obliquely to the main extension plane.

6. The optical module according to claim 1, characterized in that, The at least one first rear wall region at least segmentally defines a cavity for receiving ambient rays (44) incident on the light conductor (24) from the outside through the light exit surface (A) of the light conductor (24).

7. The optical module according to claim 1, characterized in that, The at least one first rear wall region has and / or constitutes an optical trap (31).

8. The optical module according to claim 1, characterized in that, The at least one second rear wall region has an absorbent coating at least partially.

9. The optical module according to claim 1, characterized in that, The at least one second rear wall region has nanomaterials for absorbing incident ambient radiation.

10. The optical module according to claim 1, characterized in that, The rear wall device (20) has multiple first rear wall regions of the same type and / or multiple second rear wall regions of the same type.

11. The optical module according to claim 10, characterized in that, The plurality of identical first rear wall regions and / or the plurality of identical second rear wall regions are arranged periodically.

12. The optical module according to claim 11, characterized in that, The plurality of identical first rear wall regions and / or the plurality of identical second rear wall regions are arranged in strips or grids.

13. The optical module according to claim 1, characterized in that, The at least one first rear wall region differs from the at least one second rear wall region over the entire first rear wall region by means of surface geometry, and thereby causes different reflection and / or absorption characteristics.

14. A means of transport (1), the means of transport having at least one lighting device for the means of transport, the lighting device having at least one light module according to any one of claims 1 to 13.

15. The means of transport according to claim 14, wherein, The vehicle has at least two of the aforementioned lighting devices.

16. A method for reducing color desaturation in an optical module of a lighting device (2) for a vehicle (1), wherein the color desaturation occurs under the influence of ambient radiation (44) when the optical module is used to perform its light-emitting function, wherein, The optical module has at least one light-emitting device (19) and a light conductor (24) to fulfill the light-emitting function. The light conductor is adapted and defined for guiding rays (40) originating from the light-emitting device (19) and coupled into the light conductor (24) to the light-emitting surface (A) of the light conductor (24). The optical module also has at least one rear wall device (20) that is at least partially arranged to receive ambient rays (44) incident on the light conductor (24) from the light-emitting surface (A) of the light conductor (24) from the outside. In the path, the rear wall device (20) is characterized by having at least one first rear wall region and at least one second rear wall region, wherein the ambient rays are absorbed and / or reflected by the at least one first rear wall region and the at least one second rear wall region with different intensities, wherein the rear wall device (20) is arranged relative to the light conductor such that rays emitted from the rear side from the light conductor toward the rear wall device directly hit the rear wall device, wherein the first rear wall region is a low-reflection and / or high-absorption rear wall region, and the second rear wall region is a high-reflection and / or low-absorption rear wall region.

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